The Kentucky Republican thinks they're also going to slice up the middle class, saying in a statement Monday the new rules would be a "dagger in the heart of the American middle class" that would crumble the fragile U.S. economy.

"Today’s announcement is a dagger in the heart of the American middle class, and to representative Democracy itself," McConnell said. "Already reeling from the painful effects of Obamacare, the American people are now being told they have to shoulder the burdens of the President’s latest ‘solution’ in the form of higher costs, fewer jobs, and a less reliable energy grid."

McConnell also suggested the fact the regulations were coming from the Environmental Protection Agency rather than Capitol Hill represented an "end-run around Congress" by Obama.

"The fact that the president plans to do all this through an end-run around Congress only highlights his contempt for the wishes of the public and a system of government that was devised precisely to restrain an action like today’s," said McConnell.

The new regulationsaim to force power plants to cut their emissions by as much 30% from 2005 levels by 2030. The EPA estimates the rule will cost approximately $5.5 billion in 2020, vs. net climate and health "benefits" of $26 billion to $45 billion to the economy.

The rule will likely have a disproportional effect on McConnell's home state of Kentucky, where the coal industry is a major force and McConnell is locked in a close election battle with Democratic Secretary of State Alison Lundergan Grimes. Grimes also denounced the rule Monday, calling it an "overreach" and saying she will fight the Obama administration's "attack" on coal if she wins the seat. The topic figures to be a major point of contention in the race.

Hundreds of coal plants, from where most of America's energy comes, will have to comply with the rule. Kentucky was the third-largest coal-producing state in 2012, the last year of data on record by the U.S. Energy Information Administration. Almost 93% of Kentucky's net electricity generation came from coal-fired plants.

It's likely states like Kentucky that rely on coal- and gas-powered plants will have to do more to contribute to the national 30% reduction by 2030.

McConnell highlighted the potentially disproportionate effect on Kentucky in his statement, painting the new rule as an appeasement by the Obama administration for political supporters in states like California and New York.

"By imposing these draconian new rules on the nation’s coal industry, President Obama and every other liberal lawmaker in Washington who quietly supports them is also picking regional favorites, helping their political supporters in states like California and New York while inflicting acute pain on states like Kentucky," McConnell said. "The impact on individuals and families and entire regions of the country will be catastrophic, as a proud domestic industry is decimated — and many of its jobs shipped overseas. ... In short, the downstream effects of today’s announcement will be staggering for millions."